This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Background: The NIA set aside program maintains aged rhesus monkeys at several facilities to provide for allocation to NIA-funded investigators. The current census of the NIA colony at TNPRC is 45, which is comprised of Indian-origin rhesus macaques of both sexes ranging in age from 16.5 to 23.8 years of age. Methods: The animals are housed among their original conventional breeding colony cohorts in several enclosures or they are pair housed with a compatible conspecifc in indoor housing. Results/Discussion: Since November 2002, 68 animals have been shipped to affiliate investigators. Additionally, in the last year, tissues from six animals were sent to support NIA-supported programs.